The construction of artificial playing surfaces for sporting activities has been undertaken using many different types of materials and methods. Coatings of rubber, plastic and polyurethane have been applied on top of substrates, such as asphalt, concrete or wood to achieve playing surfaces. Although these artificial surfaces do generally have the advantage of durability, they also suffer from various disadvantages, including, in various cases, high installation cost, limitations on use due to climatic factors and physical discomfort due to hardness. Moreover, even when materials are chosen to overcome some of these problems, their method of installation can leave other problems unsolved, as well as create new, otherwise unforeseen problems. For example, rubberized surfaces can ameliorate the hardness problem, but are prohibitively expensive. Also, if the rubber material is applied wet and allowed to cure in open air, the length of time needed for drying results in a surface which is often simply not smooth enough for satisfactory use in many sports, such as for playing tennis. On the other hand, latex surfaces dry more quickly and have the added benefit of substantially eliminating the possibility that toxic substances, such as accompany the use of polyurethanes, would leach into surrounding ground areas. A combination of rubberized materials with a latex-based installation method would appear to best solve these problems so as to achieve a satisfactory surface.
Added and growing problems which have not yet been solved, let alone addressed, by existing artificial all-weather playing surfaces involve the special requirements of an aging, yet active, population interested in continuing their sporting activities. Many playing surfaces fail to sufficiently slow the speed of a bouncing ball, in some cases limiting the ability of older sports enthusiasts to enjoy and participate in activities played thereon. Also, the harder the artificial surface is, the more jarring each impact while running can be on a user's knees, joints and feet. The likelihood of injuries, especially for the older user, is thereby increased. This is not only an unpleasant consequence for the sporting activist, it also increases the exposure of the surface owner to legal liability and concomitantly raises the cost of any liability insurance which the owner purchases.
One effort to solve some of these problems is typified by the patent to Becker (U.S. Pat. No. 4,341,836) in which a surface for playing tennis is constructed by dry-spreading fine grains of rubber particulate over rubber fragments embedded in a bearing layer to cover voids left between the rubber fragments. Although this surface was advantageously designed to be less rigid and to allow a tennis player to slide to a stop when moving, since the rubber particulate is not bound together, the surface is not an all-weather surface and can even lead to excessive slippage under certain conditions. Furthermore, its installation requires the use of rather expensive spraying equipment. The surface of the present invention, by contrast, advantageously provides at low cost a somewhat flexible playing surface, while retaining all-weather playing characteristics.